Murine arylsulfatase B: evidence favoring control of liver and kidney activity by two regulatory elements

C57BL/6J mice possess two- to three-fold higher arylsulfatase B activities than A/J mice in most tissues, while C57BL/6J hepatic arylsulfatase B activity is six-fold higher. These activity differences can be accounted for by the presence of greater numbers of arylsulfatase B molecules in C57BL/6J tissues. C57BL/6J and A/J arylsulfatase B appear to be catalytically equivalent and are otherwise similar within the limits of the chemical criteria employed. Genetic and developmental studies suggest the existence of a genetic element, labeled Asr-1, situated within or closely linked to As-1, the putative structural locus for arylsulfatase B, and which exhibits constitutive effects through enhancement of the expression of the cis structural locus. This element is functional in most, if not all, tissues. Evidence is presented for a second element within the As-1, region that also has a cis effect. The effects of this locus are evident after 24 days postnatal age and are confined to liver tissue. The combined effects of Asr-1 and this ill-defined temporal element produce a major portion of the six-fold higher arylsulfatase B activity occurring in C57BL/6J liver compared to A/J liver.